The government of a small but important country has decided that the alphabet needs to be streamlined and reordered. Uppercase letters will be eliminated. They will issue a royal decree in the form of a String of B and A characters. The first character in the decree specifies whether a must come ( B )Before b in the new alphabet or ( A )After b . The second character determines the relative placement of b and c , etc. So, for example, "BAA" means that a must come Before b , b must come After c , and c must come After d . Any letters beyond these requirements are to be excluded, so if the decree specifies k comparisons then the new alphabet will contain the first k+1 lowercase letters of the current alphabet. Create a class Alphabet that contains the method choices that takes the decree as input and returns the number of possible new alphabets that conform to the decree. If more than 1,000,000,000 are possible, return -1. Definition
标签： government streamline important alphabet
上传时间： 2015-06-09
上传用户：weixiao99
电力系统在台稳定计算式电力系统不正常运行方式的一种计算。它的任务是已知电力系统某一正常运行状态和受到某种扰动，计算电力系统所有发电机能否同步运行 1运行说明： 请输入初始功率S0，形如a+bi 请输入无限大系统母线电压V0 请输入系统等值电抗矩阵B 矩阵B有以下元素组成的行矩阵 1正常运行时的系统直轴等值电抗Xd 2故障运行时的系统直轴等值电抗X d 3故障切除后的系统直轴等值电抗 请输入惯性时间常数Tj 请输入时段数N 请输入哪个时段发生故障Ni 请输入每时段间隔的时间dt
上传时间： 2015-06-13
上传用户：it男一枚
上下文无关文法（Context-Free Grammar, CFG）是一个4元组G=(V, T, S, P)，其中，V和T是不相交的有限集，S∈V，P是一组有限的产生式规则集，形如A→α，其中A∈V，且α∈(V∪T)*。V的元素称为非终结符，T的元素称为终结符，S是一个特殊的非终结符，称为文法开始符。 设G=(V, T, S, P)是一个CFG，则G产生的语言是所有可由G产生的字符串组成的集合，即L(G)={x∈T* | Sx}。一个语言L是上下文无关语言（Context-Free Language, CFL），当且仅当存在一个CFG G，使得L=L(G)。 *⇒ 例如，设文法G：S→AB A→aA|a B→bB|b 则L(G)={a^nb^m | n,m>=1} 其中非终结符都是大写字母，开始符都是S，终结符都是小写字母。
标签： Context-Free Grammar CFG
上传时间： 2013-12-10
上传用户：gaojiao1999
This paper presents several low-latency mixed-timing FIFO (first-in–first-out) interfaces designs that interface systems on a chip working at different speeds. The connected systems can be either synchronous or asynchronous. The designs are then adapted to work between systems with very long interconnect delays, by migrating a single-clock solution by Carloni et al. (1999, 2000, and 2001) (for “latency-insensitive” protocols) to mixed-timing domains. The new designs can be made arbitrarily robust with regard to metastability and interface operating speeds. Initial simulations for both latency and throughput are promising.
标签： mixed-timing low-latency interfaces first-out
上传时间： 2015-10-08
上传用户：dapangxie
一:需求分析 1. 问题描述 魔王总是使用自己的一种非常精练而抽象的语言讲话,没人能听懂,但他的语言是可逐步解释成人能听懂的语言,因为他的语言是由以下两种形式的规则由人的语言逐步抽象上去的: ----------------------------------------------------------- (1) a---> (B1)(B2)....(Bm) (2)[(op1)(p2)...(pn)]---->[o(pn)][o(p(n-1))].....[o(p1)o] ----------------------------------------------------------- 在这两种形式中,从左到右均表示解释.试写一个魔王语言的解释系统,把 他的话解释成人能听得懂的话. 2. 基本要求: 用下述两条具体规则和上述规则形式(2)实现.设大写字母表示魔王语言的词汇 小写字母表示人的语言的词汇 希腊字母表示可以用大写字母或小写字母代换的变量.魔王语言可含人的词汇. (1) B --> tAdA (2) A --> sae 3. 测试数据: B(ehnxgz)B 解释成 tsaedsaeezegexenehetsaedsae若将小写字母与汉字建立下表所示的对应关系,则魔王说的话是:"天上一只鹅地上一只鹅鹅追鹅赶鹅下鹅蛋鹅恨鹅天上一只鹅地上一只鹅". | t | d | s | a | e | z | g | x | n | h | | 天 | 地 | 上 | 一只| 鹅 | 追 | 赶 | 下 | 蛋 | 恨 |
上传时间： 2014-12-02
上传用户：jkhjkh1982
Comparison of the performances of the LS and the MMSE channel estimators for a 64 sub carrier OFDM system based on the parameter of Mean square error
标签： the performances Comparison estimators
上传时间： 2016-02-01
上传用户：hgy9473
基于ARM7开发系统的触摸屏校准程序，代码中有详细的中文注释，方便用户移植……-ARM7 development system based on the touch screen calibration procedures, a detailed code of the Chinese Notes user-friendly transplantation
上传时间： 2016-11-10
上传用户：evil
Samsung S3C2440A SOC RISC Microprocessor test program that demonstrates how to code most peripherals on the chip.
标签： Microprocessor demonstrates peripherals S3C2440A
上传时间： 2013-12-20
上传用户：yulg
汉诺塔！！！ Simulate the movement of the Towers of Hanoi puzzle Bonus is possible for using animation eg. if n = 2 A→B A→C B→C if n = 3 A→C A→B C→B A→C B→A B→C A→C
标签： the animation Simulate movement
上传时间： 2017-02-11
上传用户：waizhang
This is schematic and Gerber files of PCB that is used for GPS tracking device with GSM link. Scheme has many valuable schematic features, like protected digital and analog I/Os, power part adapted for car power supply, etc. Can be used as a reference design for anyone who wants to make own GPS GSM tracking system based on SIM508 module from Simcom.
标签： schematic tracking Gerber Scheme
上传时间： 2013-12-19
上传用户：chfanjiang
